如何获取CSV文件的特定字段? [英] How can I get a specific field of a csv file?

问题描述

我需要一种获取CSV特定项目(字段)的方法.假设我有一个包含100行和2列的CSV(逗号分隔).第一栏电子邮件，第二栏密码.例如，我想在第38行中获取电子邮件的密码.因此，我只需要第二列第38行中的项目...

I need a way to get a specific item(field) of a CSV. Say I have a CSV with 100 rows and 2 columns (comma seperated). First column emails, second column passwords. For example I want to get the password of the email in row 38. So I need only the item from 2nd column row 38...

说我有一个csv文件:

Say I have a csv file:

[e-mail],bbbbb
[e-mail],ddddd

例如，如何仅获得"ddddd"?

How can I get only 'ddddd' for example?

我是该语言的新手，尝试使用csv模块进行一些操作，但我不明白...

I'm new to the language and tried some stuff with the csv module, but I don't get it...

推荐答案

import csv
mycsv = csv.reader(open(myfilepath))
for row in mycsv:
   text = row[1]

在此处的注释之后，最好的，更健壮的代码是:

Following the comments to the SO question here, a best, more robust code would be:

import csv
with open(myfilepath, 'rb') as f:
    mycsv = csv.reader(f)
    for row in mycsv:
        text = row[1]
        ............

更新:如果OP真正想要的是csv文件最后一行中的最后一个字符串，则有一些方法不一定需要csv.例如，

Update: If what the OP actually wants is the last string in the last row of the csv file, there are several aproaches that not necesarily needs csv. For example,

fulltxt = open(mifilepath, 'rb').read()
laststring = fulltxt.split(',')[-1]

这不适用于大文件，因为您可以将完整的文本加载到内存中，但对于小文件则可以.请注意，laststring可能包含换行符，因此请在使用前将其删除.

This is not good for very big files because you load the complete text in memory but could be ok for small files. Note that laststring could include a newline character so strip it before use.

最后，如果OP想要的是第n行中的第二个字符串(对于n = 2):

And finally if what the OP wants is the second string in line n (for n=2):

更新2:现在，此代码与J.F. Sebastian回答中的代码相同. (功劳是他的):

Update 2: This is now the same code than the one in the answer from J.F.Sebastian. (The credit is for him):

import csv
line_number = 2     
with open(myfilepath, 'rb') as f:
    mycsv = csv.reader(f)
    mycsv = list(mycsv)
    text = mycsv[line_number][1]
    ............

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